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1 package polyglot.visit;
2
3 import polyglot.ast.*;
4 import polyglot.types.TypeSystem;
5 import polyglot.frontend.Job;
6 import polyglot.util.Position;
7
8
9 public class ConstantFolder extends NodeVisitor
10 {
11 TypeSystem ts;
12 NodeFactory nf;
13
14 public ConstantFolder(TypeSystem ts, NodeFactory nf) {
15 this.ts = ts;
16 this.nf = nf;
17 }
18
19 public TypeSystem typeSystem() {
20 return ts;
21 }
22
23 public NodeFactory nodeFactory() {
24 return nf;
25 }
26
27 public Node leave(Node old, Node n, NodeVisitor v_) {
28 if (! (n instanceof Expr)) {
29 return n;
30 }
31
32 Expr e = (Expr) n;
33
34 if (! e.isConstant()) {
35 return e;
36 }
37
38 if (e instanceof Binary) {
41 Binary b = (Binary) e;
42
43 if (b.operator() == Binary.ADD &&
44 b.left().constantValue() instanceof String  &&
45 b.right().constantValue() instanceof String ) {
46
47 return b;
48 }
49 }
50
51 Object v = e.constantValue();
52 Position pos = e.position();
53
54 if (v == null) {
55 return nf.NullLit(pos).type(ts.Null());
56 }
57 if (v instanceof String ) {
58 return nf.StringLit(pos,
59 (String ) v).type(ts.String());
60 }
61 if (v instanceof Boolean ) {
62 return nf.BooleanLit(pos,
63 ((Boolean ) v).booleanValue()).type(ts.Boolean());
64 }
65 if (v instanceof Double ) {
66 return nf.FloatLit(pos, FloatLit.DOUBLE,
67 ((Double ) v).doubleValue()).type(ts.Double());
68 }
69 if (v instanceof Float ) {
70 return nf.FloatLit(pos, FloatLit.FLOAT,
71 ((Float ) v).floatValue()).type(ts.Float());
72 }
73 if (v instanceof Long ) {
74 return nf.IntLit(pos, IntLit.LONG,
75 ((Long ) v).longValue()).type(ts.Long());
76 }
77 if (v instanceof Integer ) {
78 return nf.IntLit(pos, IntLit.INT,
79 ((Integer ) v).intValue()).type(ts.Int());
80 }
81 if (v instanceof Character ) {
82 return nf.CharLit(pos,
83 ((Character ) v).charValue()).type(ts.Char());
84 }
85
86 return e;
87 }
88 }
89 |
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